The present invention relates to a protective element for a sealing arrangement with at least one sealing ring wherein the protective element has a bottom and a mantle portion through which the shaft to be sealed extends and wherein the bottom at the radially inner end has a cylindrical portion.
The invention further relates to a sealing arrangement for a shaft, preferably of a motor vehicle, comprising a protective element as disclosed above wherein at least one sealing ring is provided that is at least partially covered by the protective element. The invention also relates to a method for keeping away dirt particles from a sealing arrangement embodied as disclosed above.
For a rotatably driven and axially moveably shaft as used in motor vehicles, dirt particles will collect thereon when driving straight. When turning the steering wheel the dirt particles, will be pushed away because the shaft is axially moved. The protective element is cup-shaped and seated in front of the sealing arrangement. Fine dirt particles however can penetrate through this cup-shaped protective element into the sealing arrangement. When further dirt collects while driving straight, the dirt behind the protective element will be compressed and collected in a chamber. Upon multiple turning actions of the steering wheel, a deformation of the protective element or of the sealing arrangement will result.
It is therefore an object of the present invention to embody the aforementioned protective element, the aforementioned sealing arrangement as well as the aforementioned method such that dirt particles will not lead to an untimely breakdown of the protective element, respectively, the sealing arrangement.
This object is inventively solved for the aforementioned protective element in that the free end face of the cylindrical portion is, when viewed in an axial section, slanted relative to the axis of the cylindrical portion at least over a portion of its circumference.
The object is solved for the aforementioned sealing arrangement by such a protective element and for the aforementioned method by exerting a force during rotation of the shaft or of the shaft housing in a direction away from the sealing arrangement.
The protective element, according to the invention, is thus provided with a free end face of the cylindrical portion that at least over a portion of its circumference is slanted. Advantageously, the entire end face of the cylindrical portion is positioned at a slant to the axis of the cylindrical portion. When a rotation about 360xc2x0 is performed, the developed view of this end face results in a sinus-shaped course. Because of the dynamic action of the rotation of the shaft or of the housing, the sinus-shaped course of the end face during driving causes a permanent axial pushing force which prevents the attachment of dirt particles on the shaft. In this manner it is reliably prevented that the protective element, respectively, the sealing arrangement will experience early failure.